Toner formulation and method of preparing the same

Abstract

A chemically prepared toner composition made up of a toner particle with a core having a first polymer binder, a monomer free radical polymerization formed core shell styrene acrylic latex having a liquid gel core, a pigment, a wax, and a shell formed around the core including a second polymer binder and method to make the same is disclosed. An optional borax coupling agent can be placed between the outer surface of the core and the shell to assist in the binding of the polymer found in the shell onto the surface of the toner core containing the first polymer.

What is claimed is: 
     
       1. A method of producing toner comprising:
 preparing a core shell latex having a liquid gel core, the preparing of the core shell latex including the steps of:
 (a) preparing a latex; 
 (b) preparing a monomer solution; 
 (c) seeding the latex with a portion of the monomer solution, a plasticizing oil, a cross linking agent and chain transfer agent, wherein the liquid gel core is formed; 
 (d) preparing an initiator solution; and 
 (e) adding the initiator solution and a remaining portion of the monomer solution to the formed liquid gel core to create a shell for the formed liquid gel core; 
 
 preparing a first polymer emulsion; 
 preparing a second polymer emulsion; 
 preparing a wax emulsion; 
 preparing a pigment dispersion; 
 combining and agglomerating the first polymer emulsion with the pigment dispersion, wax emulsion and the core shell latex having a liquid gel core to form toner cores; 
 combining and agglomerating the second polymer emulsion with the toner cores to form toner shells around the toner cores; and 
 fusing the aggregated toner cores and toner shells to form toner particles, wherein the formed toner particles have a core shell structure. 
 
     
     
       2. The method of  claim 1 , wherein the monomer solution includes a hydrophilic monomer having carboxyl (—COOH) and hydroxy (—OH) functional groups and a hydrophobic monomer having styrene and acrylate functionality. 
     
     
       3. The method of  claim 2 , wherein the hydrophobic monomer having acrylate functionality is an alkyl acrylate. 
     
     
       4. The method of  claim 3 , wherein the alkyl acrylate monomer is lauryl acrylate. 
     
     
       5. The method of  claim 1 , wherein the plasticizing oil is a hydrocarbon oil having 10 or more carbons. 
     
     
       6. The method of  claim 2 , wherein the hydrophilic monomers having carboxyl (—COOH) and hydroxy (—OH) functional groups are hydroxyethyl methacrylate and beta-carboxyethyl acrylate. 
     
     
       7. The method of  claim 1 , wherein the glass transition temperature (Tg) of the latex is between 20° C. and 60° C. 
     
     
       8. The method of  claim 1 , wherein the first polymer emulsion and the second polymer emulsion each include a polyester resin. 
     
     
       9. The method of  claim 8 , wherein the first polymer emulsion includes a first polyester resin or mixture and the second polymer emulsion includes a second polyester resin or mixture different from the first polyester resin or mixture. 
     
     
       10. The method of  claim 1 , further comprising the step of adding a borax coupling agent to the surface of the formed toner cores and then performing the step of combining and agglomerating the second polymer emulsion with the formed toner cores having the borax coupling agent on its surface to form toner shells around the toner cores. 
     
     
       11. A toner prepared by the process of  claim 1 . 
     
     
       12. A method of producing toner comprising:
 preparing a core shell latex having a liquid gel core, the preparing of the core-shell latex including the steps of:
 (a) preparing a latex; 
 (b) preparing a monomer solution; 
 (c) seeding the latex with a portion of the monomer solution, a plasticizing oil, a cross linking agent and chain transfer agent, wherein the liquid gel core is formed; 
 (d) preparing an initiator solution; and 
 (e) adding the initiator solution and a remaining portion of the monomer solution to the formed liquid gel core to create a shell for the formed liquid gel core; 
 
 preparing a first polymer emulsion; 
 preparing a second polymer emulsion; 
 preparing a wax emulsion; 
 preparing a pigment dispersion; 
 combining and agglomerating the first polymer emulsion with the pigment dispersion, wax emulsion and the core shell latex having a liquid gel cores to form toner cores; 
 combining and agglomerating the second polymer emulsion with the toner cores to form toner shells around the toner cores; 
 adjusting the pH of the combination of the first polymer emulsion with the pigment dispersion, the wax emulsion and the monomer encapsulated liquid gel latex to promote agglomeration of the toner cores; 
 combining and agglomerating the second polymer emulsion with the toner cores to form toner shells around the toner cores; 
 once a desired toner particle size is reached, adjusting the pH of the mixture of the aggregated toner cores and toner shells to prevent additional particle growth; and 
 fusing the aggregated toner cores and toner shells to form toner particles, wherein the formed toner particles have a core shell structure. 
 
     
     
       13. The method of  claim 12 , wherein the monomer solution includes a hydrophilic monomer having carboxyl (—COOH) and hydroxy (—OH) functional groups and a hydrophobic monomer having styrene and acrylate functionality. 
     
     
       14. The method of  claim 13 , wherein the hydrophobic monomer having acrylate functionality is an alkyl acrylate. 
     
     
       15. The method of  claim 14 , wherein the alkyl acrylate monomer is lauryl acrylate. 
     
     
       16. The method of  claim 13 , wherein the hydrophilic monomers having carboxyl (—COOH) and hydroxy (—OH) functional groups are hydroxyethyl methacrylate and beta-carboxyethyl acrylate. 
     
     
       17. The method of  claim 12 , wherein the first polymer emulsion and the second polymer emulsion each include a polyester resin. 
     
     
       18. The method of  claim 17 , wherein the first polymer emulsion includes a first polyester resin or mixture and the second polymer emulsion includes a second polyester resin or mixture different from the first polyester resin or mixture. 
     
     
       19. The method of  claim 12 , further comprising the step of adding a borax coupling agent to the surface of the formed toner cores and then performing the step of combining and agglomerating the second polymer emulsion with the formed toner cores having the borax coupling agent on its surface to form toner shells around the toner cores.